Dry pan



0. BROWN. DRY PAN.

APPLICATION FILED DEC.20, 1918.

1,390,235 PatentedSeptu 6, 1921..

2 SHEETS-SHEET i.

b M W D. BROWN.

DRY PAN.

APPLICATION FILED 020.20, 19 18.

Patented Sept. 6, 1921.

2 SHEETS-SHEET 2.'

nnvrs BROWN, or BUCYRUS, OHIO, assrcivon T0 HADFIELD rnnrrnnn srnnr.

COMPANY, OF BUCYRUS, OHIO, A QORPQRATION To all whom it may conoernl.

Be it known that I, DAVIS: BROWN, a citizen of the United States, and a resident of Bucyrus, Ohio, have invented an. Improvement in Dry Pans, of which the following description, in connection with the accompanying drawings, is a specification, like letters on the drawings representing like parts. I

The present invention is an improved screen plate for dry pans, being a divisional of my prior application, Serial Number 207,043, filed December 14, 1917, upon the process of making the plates claimed herein.

As explained in said co-pending appllcation, the screen bars or grids must withstand very heavy strains and cast iron has been found insuflicient for this work and the present invention consists in the discovery of a practical method of building the cast iron ramework with rolled steel bars. In manufacturing the screen plates of my present invention I provide the usual pattern for casting the frame of the screen around the outer side, but. I so arrange an intermediate section for supporting the inner ends of the grids as to form same first in relatively thin metal portions capable of springing during the cooling of the frame without danger of distorting the heavier outside rims. I accomplish this by first forming the middle section or partition in a usual manner and then fitting a core through the middle section of the mold for this middle partition, throughout the mold in desired proximity with their outer ends in line to fitwithin the casting and the inner ends within one of the relatively thin middle partitions cast by-the application of the core through the middle mold as above explained. The iron is then cast to form the frame, firmly engaging and holding the respective ends of the steel grids, and permitted to cool. e During this cooling, the contraction of the frame may draw the inner thin partitions somewhat, but said inner partitions are so formed as to spring and permit this contraction. Thereafter the middle section is again fitted in a mold, and the space from which the core has been removed is filled u with molten iron, as a separate casting. Freferably the second casting is made to dovetail with Specification of Letters Patent.

improved screen applying the steel bars OF OHIO.

DRY PAN.

Patented Sept. 6, 1921.

207,043. Divided and this application filed Serial no. 267,651.

or interlock about which were originallymade for the central partitions. an improved screen, with an iron frame and steel grids Y which has beenmade in a feasible,

minimum of cost, automatically taking care of the normal tend mold, bars from buckling when cooling.

eferring to the drawingsillustrating a preferred embodiment of the invention,

igure 1 is a view of a dry pan;

Fig. 2 is an enlarged view of one of the screen plates ,2

. ig. 3 is a cross-sectional view on the line Figs. 4 and 5 and6 t e connections between andth'e cast iron frame. y

I have shown in. the drawings, for illustratlve purposes, the type of dry pan such asthat illustratedin patent to R. C. Penthe steel grid barsfield, No; 974,818, dated November 8, 1910,

wherein the dry pan is built foundation or framework side frames 2, a central upon the 1, having suitable partly in cross section are detailed views of drive shaft-3, suitable mechanism for supporting the mullers 4, the main grinding base or hub 5, radial carry ng flanges. 6, and cylindrical rim 7 carrylng the screen plates 8, arranged in segmental sections around the revolving pan.

Each screen section, as illustrated in Fig. 2 comprises a frame with the inner rim concentric arcs and of a size suitable for the diameter of dry pan in whichthey are to be employed. This section is further formed with radial frame portions 12 and 13 are each formed as shown in Fig. 4 with a dovetailed recess as indicated at 14 to receive the correspondingly shaped end 15 of a steel grid bar 16. Preferably these recesses 14 are made in groups of three or four, four such being shown at 17, 17, 17, 17, in the drawings. This permits a set of four grid bars of the same length to be interchangeably fitted at appropriate sections throughout the screen.

The dovetailing arrangement of the steel frame on cooling down line 6-6 of Fig. 2, the ment for the reinforcing tions 12 and 13 as just described, is readily accomplished by fitting the bars therein before the central partition 20 is formed. As shown in Fig. 5, the inner ends of the steel bars 16 are similarly dovetailed and fitted into a thin spacing and carrying member 2 and 21, which members 21 are appropriately spaced from each other to permit the subsequent pouring of the iron to form the rest of the middle partition 20. I prefer to form these thin divisionalwalls of irregular shape, such as, for example, on the curved lines 22, 22, in order to provide an interlocking when the restrof viz. the member 20, is cast therein.

he pattern is molded in the same in the usual way, then the pattern is withdrawn and a dry sand core, substantially of the form shown at 20, Fig. 2, and the steel bars, '16, are placed in the sand in their proper places. The mold is then closed and the cast iron poured around the bars 16 and the core in the place of the member 20. After cooling the casting is removed from the sand and cleaned. The core being cleaned out leaves a space between the two division walls 21. In cooling, the cast iron frame shrinks closing in on the bars and forces them toward the center and the center division walls 21, which being purposely lighter and weaker than the other and outer walls of the frame will spring or maybe break away from the main frame at the junction points and this is what prevents buckling of the bars or weakening of the main frame when it contracts in cooling. The space between the two light division walls 21 permits them to spring toward or from each other and relieve the bars and the main frame of the strains caused by the shrinkage of the cast from the molten state. The bars are not subject to this shrinkage.

After cooling down and cleaning, the frame is again placed in the sand and the space between the two light center walls and additional space below these light partition walls is poured filling the vacant space between them and formingv a permanent support beneath them, interlocking, solidifying, and strengthening the center partition 20, 21 and 21 being a substantially solid member.

My invention thus combines steel grid bars with the cast iron frame, and secures the advantages of a simple and economical construction, presenting a screen plate with the desired increase in'area of openings and iron many times over.

Fig. 6 illustrates, in crossssection, on the present arrangepoured metal 20 this middle partition member, and then to strengthen and defined in the iron, steel described,

1 tion consists in cast iron framework with steel grid bars, preferably built so that the steel bars and cast iron framework may contract during cooling without unduly disbuckling the bars.

prefer to form one of the cast iron supports for the steel grids thinner than the other to permit it to spring, as above explained,

this thinner supporting member by an additional bracing frame, preferably cast thereon and interlocking therewith. In the form shown, this thinner member subsequently strengthened and reinforced, is the middle supporting bar for the screen plate, and it could as well beone' ofthe side members, if desired.

My present invention is further described form of claims as follows:

1. A screen plate for dry pans, of the kind described, consisting in a framework of cast grid bars being cast with the framework, said framework including a middle partition supporting the inner ends ofthe steel grid bars, said middle partition being composed ofrelatively thin cast iron members supporting and spacing the inner ends of the bars and an interposed support ing, spacing and strengthening member.

2. A screen plate for dry pans, of the kind described, comprising a framework of cast iron including relatively thick side plates and a relatively thin center plate composed of relatively thin members having an interposed spacing and strengthening member, steel grid bars extending between said plates and having the ends thereof intimately associated withsaid plates.

3. A screen platefor dry pans, of the kind including a framework of cast iron having arelatively thickside plate and a pair of relatively thin center plates, spaced apart from each other, a plurality of parallel dovetails arranged longitudinally of said side plate, a single dovetail arranged longitudinally of the said center plate, a plurality of groups of steelgrid bars extending etween the plates, one group in each of the parallel dovetails, and a strengthening bar arranged between the pair of relatively thin center plates. 7

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses. with steel grids which will outlast the cast 7 DAVIS BROWN. 

